effect of acupoint electrical stimulation on incidence of hypotension after spinal anesthesia

Conditions: Anesthesia

Summary: this study is intended to include elderly patients who are selected to undergo lower limb and pelvic orthopedic surgery under spinal anesthesia. through prospective, randomized and controlled clinical trials, the investigators will observe the effect of this treatment on the incidence of hypotension in elderly patients after spinal anesthesia through teas points neiguan and quchi before or during surgery, and further explore its related mechanisms.

research content: this study aims to observe whether teas intervention on neiguan (pc-6) and quchi (li-11) before and during operation can improve the incidence and degree of hypotension after spinal anesthesia, as well as the changes of neurotransmitters and related hormones in blood. research methods: * 111 elderly patients (including hip or lower limb fractures, hip and knee joint replacement or debridement) who were selected for lower limb or pelvic surgery under spinal anesthesia were randomly divided into percutaneous point electrical stimulation pretreatment group (pteas group), percutaneous point electrical stimulation treatment group (teas group) and percutaneous point pseudo electrical stimulation group (fteas group). * after entering the operating room, the vital signs were monitored routinely, and the volume was evaluated by measuring the variability of the inferior vena cava with ultrasound before anesthesia. then, the radial artery was punctured and catheterized, and sodium lactate was infused (8ml/kg). * within 30 minutes before spinal anesthesia or 30 minutes after hypotension, teas (density wave 10/50hz, one side of neiguan and quchi points connected to two electrodes on the same wire on the electroacupuncture instrument) was continuously performed on both sides of neiguan and quchi points, and the current intensity was only as high as the patient could comfortably tolerate (the electrical stimulation intensity was 2-3 times of the sensory threshold, for example, if the electrical stimulation intensity was 5 ma, 10-15 ma was used for stimulation), record the specific value of current. fteas group pastes electrode piece, turns on the power, but there is no current output. * select l2/3 or l3/4 interval for spinal anesthesia, use 0.75% cloth ratio, and the dose standard is 0.025ml/kg. * collect venous blood after entering the operating room and 30 minutes after anesthesia to measure the levels of neurotransmitters and hormones, record the baseline value of vital signs and changes during operation, observe the occurrence and treatment of adverse events during operation, and follow up the troponin t level and the incidence of delirium after operation. * remedial measures for clinical safety: when severe hypotension occurs during operation, which leads to irreversible adverse effects, it needs to be intervened by multiple means. those who are diagnosed as delirium through cam determination shall be treated with haloperidol or dexmedetomidine.

Eligibility criteria:
inclusion criteria: * 90\>65, regardless of gender; * asa classification i-iii; ③ orthopedic surgery was performed under spinal anesthesia; ④ sign the informed consent form. exclusion criteria: * uncontrolled hypertension; * arrhythmia or myocardial ischemia; * severe cardiopulmonary insufficiency; * hb\<100g/l; * severe dehydration; ⑥ there are contraindications to spinal anesthesia; ⑦ allergies to local anesthetics; * communication barriers; ⑨ refusing to sign the informed consent form.